For a future mobile communication system, more and more access nodes will inevitably be introduced, i.e., an Ultra Dense Network (UDN) will emerge, so as to meet the user's requirement in a better manner as well as to remarkably increase the network capacity and throughput.
In a UDN architecture, there is a small distance between the deployed nodes and each node has a small coverage, so the number of the access nodes is extremely large and a resultant network structure is more complex. At this time, such a problem in mobility management may occur. In order to perform mobility management on the UDN efficiently and improve the overall performance and efficiency of the UDN, cell virtualization may be adopted. In this way, it is able to weaken the identification of a user equipment (UE) on each single cell and region information, thereby to enable the UE to manage and move in a larger virtual region.
However, during the cell virtualization operation in the UDN architecture, a cell identifier and region information may change significantly, and it may be unnecessary for the UE to identify the cell any more. Instead, it is merely necessary for the UE to transmit data efficiently through available resources. Hence, in the UDN architecture, a conventional method of managing and addressing UE's position and attribution at a network side is no longer applicable, and there is an urgent need to find a new scheme to address the UE at the network side so as to complete various called services.